SAN ANGELO, Texas – A court began laying the groundwork Monday to sort out the custody arrangements for hundreds of young children seized from a polygamist sect, with nearly four dozen lawyers seeking to represent the children in attendance.

State District Judge Barbara Walther held the hearing to prepare for Thursday's expected marathon session, when the state will plea for permanent custody of the 416 children taken early this month from the Eldorado ranch of the Fundamentalist Church of Jesus Christ of Latter Day Saints, a renegade Mormon sect.

Gary Banks, a lawyer representing the state Children's Protective Services, told the judge the state believes "there is a systematic process at the ranch near Eldorado at which children were exploited and sexually abused."

The children were rounded up and placed in temporary custody in a raid that began April 3 after a domestic violence hot line recorded a complaint from a 16-year-old girl. She said she was physically and sexually abused by her 50-year-old husband.

Walther was clearly struggling with how to organize what is believed to be the largest child-custody hearing in Texas history, and perhaps in the nation. Texas bar officials say more than 350 attorneys from across the state have volunteered to represent the children for free. Child welfare laws require each child in state custody to have an attorney.

"If I gave everybody five minutes, that would be 70 hours," Walther said, stressing a need for efficiency as well as the protection of the children's rights.

Three mothers of the children have appealed to Gov. Rick Perry for help in a letter the sect said was mailed to him on Saturday.

In the letter, a copy of which was obtained by The Associated Press, the mothers from the Fundamentalist Church of Jesus Christ of Latter Day Saints claim some of their children have become sick and even required hospitalization. They also say children have been questioned about things they know nothing about since they were placed in the legal custody of the state.

The one-page letter, signed by three women who claim they represent others, says about 15 mothers were away from the property when their children were removed. The mothers said they want Perry to examine the conditions in which the removed children have been placed.

"You would be appalled," the letter said. "Many of our children have become sick as a result of the conditions they have been placed in. Some have even had to be taken to the hospital. Our innocent children are continually being questioned on things they know nothing about. The physical examinations were horrifying to the children. The exposure to these conditions is traumatizing them."

Perry spokesman Robert Black said Monday that the letter hadn't yet arrived. Black also said the governor was being briefed daily on the situation but didn't plan to interfere with the work of state child welfare or law enforcement agencies.

Asked about claims that children were hospitalized, state Child Protective Services spokeswoman Marissa Gonzalez said she had not seen the letter and would have to review it before commenting. Officials have said that about a dozen children had chicken pox and that others needed prescription medications but hadn't said whether any were hospitalized.

The children are being housed in San Angelo's historic Fort Concho and at the nearby Wells Fargo pavilion. About 140 women from the ranch are also with the children, although they are not in state custody.

On Saturday, five FLDS women staying at the fort told Salt Lake City's Deseret News that the temporary shelter is cramped — cots, cribs and play pens are lined up side by side — and that many of the children are frightened.

An FLDS member who told the AP that his family members are among those inside the fort called the removal of phones a punishment.

"This was nothing more than retaliation of CPS to punish those who were disclosing what is really happening behind that wall of this concentration camp," said Don, who asked that only his first name be used because of the custody hearings.

Affidavits filed by child protection workers said they found a pattern of abuse at the Yearning for Zion ranch in Eldorado, about 45 miles south of San Angelo.

The 1,700-acre fenced ranch, a former game preserve, was bought by the FLDS in 2003. A number of large dormitory-style homes have been built, along with a small medical center, a cheese factory, a rock quarry, a water treatment plant and a towering, white limestone temple.

The FLDS practices polygamy in arranged marriage that often pair underage girls with older men. The faith believes the practice will brings glorification in heaven. The mainstream Mormon church, the Church of Jesus Christ of Latter-day Saints, does not practice polygamy.